Perianal

Located around the anus, the opening of the rectum to the outside of the body.

Peri- is a prefix borrowed from the Greek.

It means 'around or about.' So pericardial is around the heart.

Perinatal is around birth.

And periumbilical is around the umbilicus (the belly button).

Peri- is a useful prefix in anatomy and so is much employed in medicine.

Pericardial fluid is fluid around the heart.

Periaortic lymph nodes are lymph nodes around the aorta.

A perianal abscess is an abscess (a local accumulation of pus) that forms next to the anus causing tender swelling in that area and pain on defecation